<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <title>Document</title>
    <style>
    .halo{
        width: 100px;
        height: 100px;
        background-color: red;
    }
    .hidden{
        display: none;
    }
    .changeColor{
        width: 100px;
        height: 100px;
        background-color: green;
    }
    </style>
</head>
<body>
    <div id="app">
        <div v-bind:class="halo">halo</div>
        <div v-bind:class="{hidden:isHidden,changeColor:isChange}">this is</div>
        <div>441</div>
        <button @click="click">click</button>
    </div>

    <script>
        new Vue({
            el:"#app",
            data:{
                halo:"halo",
                isHidden:false,
                isChange:true
            },
            methods:{
                click(){
                    this.isHidden=true
                }
            }
        })
    </script>
</body>
</html>